deliver
creates a single executable file. However graphical Macintosh applications consist of an application bundle, which is a folder
Foo.app
with several subfolders containing the main executable and other resources.
LispWorks for Macintosh is supplied with example code that constructs an application bundle. It is convenient to use this code - or your variant of it - at delivery time, so that your delivered executable is ready to run in its application bundle in the usual Mac OS X way. See Creating a Mac OS X application bundle for an illustration of this.
There is another example in
examples/configuration/save-macos-application.lisp
. This code is actually a
save-image
script (rather than
deliver
) but it shows how to avoid writing the application bundle twice when saving a universal binary application.